Vestibular disorders represent a debilitating medical problem by causing balance and vision impairments that adversely affects the lives of people of all ages and backgrounds. The restoration of vestibular function by direct stimulation of the vestibular nerve, bypassing the sensory organs, is expected to alleviate these symptoms in some patients. Currently, there are no clinically available treatments to restore the loss of this sensory information. In other collaborative efforts, Aculight has developed an infrared nerve stimulation device that has demonstrated success in peripheral nerve and cochlear nerve stimulation. Based on the principles of nerve stimulation with an infrared laser, the objective of the proposed work is to apply this technology to current research at the University of Washington by developing and testing a compact, multi-channel vestibular prosthesis. The use of this new stimulation technique can circumvent the limitations that currently prohibit development of an efficient vestibular prosthetic device. In the Phase 1, we will develop and test a single channel laser nerve stimulator designed to suit the specific needs of vestibular nerve stimulation. The Phase 2 efforts will expand the functionality of the device to have multiple independent channels with a more compact design interfaced to an implantable light delivery system. Laser parameters will be refined through testing in awake animals. Ultimately, the device will be used to test the refined chronically implantable light delivery probe coupled to the optimized multi- channel device for use in primates. These stated goals will produce a laser-based stimulation device suitable for research in vestibular prostheses and other applications where discrete nerve stimulation is required. If successful, we will continue to partner with leading research institutions to expand the applicability of the infrared nerve stimulation research tool and, ultimately, to commercialize a fully implantable vestibular prosthesis for human patients. Project Narrative This project is intended to benefit those that have lost vestibular function through disease or injury by developing a tool for research in vestibular implants as well as developing a vestibular implantable prosthetic device. This research will focus on overcoming the limitations prohibiting current vestibular implant research, which will allow people to stabilize balance and vision that is impaired by the lack of vestibular function. [unreadable] [unreadable] [unreadable]